Physicists at the University of Colorado Boulder have announced the creation of the world’s first visible “time crystal” that can be seen with a microscope or even with the naked eye under certain conditions.
Described by the UC Boulder team as a “curious phase of matter in which the pieces, such as atoms or other particles, exist in constant motion,” time crystals that are visible could enable a wide range of currently unavailable applications, such as advanced anti-counterfeiting technologies and “time barcodes.”
“Everything is born out of nothing,” explained Ivan Smalyukh, a UC Boulder professor of physics and fellow with the Renewable and Sustainable Energy Institute (RASEI) and co-author of the study detailing the team’s findings. “All you do is shine a light, and this whole world of time crystals emerges.”
When Nobel laureate Frank Wilczek first proposed the concept of a time crystal in 2012, scientists challenged readers to consider a physical crystal, such as a diamond, as a “space crystal,” since its internal atomic structure was aligned in space. Conversely, a time crystal is aligned over time since it is in constant motion.
While scientists have determined that building an actual time crystal that operates like a clock without a battery is likely impossible, they have created several versions of time crystals that mostly function in the same way. Still, those few successful examples were extremely small or fleeting, making them unusually difficult to directly visualize.
Hoping to create the world’s first visible time crystal, the UC Boulder team designed an experiment using liquid crystals like the ones used in smartphone displays. According to Smalyukh, squeezing the molecule within liquid crystals in the right way will cause them to bunch together and form “kinks.” Under certain conditions, these kinks can even behave like atoms.
“You have these twists, and you can’t easily remove them,” Smalyukh said. “They behave like particles and start interacting with each other.”
To see if they could coax this motion into something resembling a time crystal, Smalyukh and Hanqing Zhao, the lead author of the study and a graduate student in the Department of Physics at CU Boulder, placed a solution of liquid crystals in between two pieces of glass. To help the scientists see any possible motion, they coated the glass with dye molecules.
According to the team’s statement, the samples “mostly sat still.” However, when the researchers shone a certain wavelength of laser on the samples, the molecules in the dye suddenly changed their orientation. The resulting “squeeze” placed on the liquid crystal caused thousands of kinks to suddenly form. These formations of kinks triggered a series of interactions that the authors likened to a room filled with dancers in a Jane Austen novel.
“Pairs break apart, spin around the room, come back together, and do it all over again,” they explain.
After some experimentation, the team found that the “patterns in time” were also unusually hard to break, even if they raised or lowered the temperature. Although not perfect, the team concluded that they had essentially created a crystalline structure that is in constant motion, or a time crystal. Perhaps even more importantly, their experimental setup was simple and reproducible.
“That’s the beauty of this time crystal,” Smalyukh said. “You just create some conditions that aren’t that special. You shine a light, and the whole thing happens.”
Perhaps the most striking aspect of the UC Boulder team’s time crystal is that it is visible. For example, when the team placed the sample underneath a microscope, they noted that it created a repeating pattern that resembled “psychedelic tiger stripes.” The pattern also continued to repeat for hours after a single laser shot without losing its visibility.
“They can be observed directly under a microscope and even, under special conditions, by the naked eye,” Zhao said.
In the study’s conclusion, the team said that this visibility could open a wide range of potential applications. One example proposed by the authors involved incorporating these types of liquid crystal structures into currency “to make them harder to counterfeit.”
“If you want to know if that $100 bill is genuine, just shine a light on the ‘time watermark’ and watch the pattern that appears,” they explain.
Another potential use involved stacking a visible time crystal on top of another. A video released in conjunction with the study shows how this type of stack of visible time crystals can create a completely unique “time barcode.”
Smalyuhk said the team sees several possibilities. However, they don’t want to put a limit on the potential applications until further research is completed.
“I think there are opportunities to push this technology in all sorts of directions,” the researcher concluded.
The study “Space-time crystals from particle-like topological solitons” was published in Nature Materials.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.